The replacement process of a photoresist filter in a photoresist distribution system can include circulating photoresist through the photoresist filter unit to pre-wet the filter and to remove air trapped in the filter. Consequently, the photoresist that circulates through the filter can be infused with air bubbles. Photoresist with air bubbles cannot be used during the photoresist process and as a result, must be discarded. The discarded photoresist adds cost to the semiconductor fabrication process.